Sealey Ak5513 Impact Extension Bar Set 4Pc 1/2Sq Drive

Product Information

At this point, a pattern had been found that as the extension length kept increasing, the torque loss was higher (without the brace). To see if the pattern was valid or not, things were stretched out even further.

Desired Torque? Well, you know that—it’s the torque you want to be ultimately applied to the fastener. But here’s the upfront conclusion if you’re a skimmer—the extension does not cause torque loss as long as it’s perfectly perpendicular to the body of the wrench. But achieving the perfect angle is often tougher than it’s thought to be. In simpler terms, an extension that’ll increase the effective length of the wrench will need to be adjusted for. An increased effective length will provide more leverage than default and thus will apply a different amount of pressure than intended, killing the sole purpose of a torque wrench. Now, while trying out the same extension but this time without the chair as the brace, it to no surprise, again lost some torque, averaging out at 33.5 ft-lb representing a 3.74% loss from the baseline.In the first attempt, the extension was kept straight and it averaged out at 33.7 ft-lb as an average of 3 results as always, which is the same as the ½-inch drive impact extension that was first used. Well, it’s the case for straight extensions. Basically, any offset or extension that changes the distance between the centerline of the wrench drive and the centerline of the fastener needs to be adjusted. All these attempts were made from completely different angles, intentionally. The inconsistency of the outcome validates the hypothesis. What Causes Torque Loss? So to settle things, yes, you can use an extension with a torque wrench without losing on torque and keeping the purpose intact as long as you can keep it perpendicular (or as close as possible) to the body of the wrench. Adjusting for The Extension According to physics, if you keep the extension perfectly perpendicular to the body of the wrench, there should be no torque loss—and that’s actually the case, as seen on many tests. When similar tests were carried out, ensuring the conditions were met, there was no real torque loss.

Some wrenches will have a marking on the handle for reference, and that’s the point to measure up to from the center of the drive. If the marking isn’t there, take the middle point of the handle as your reference. Halfords Advanced hand tools come with a Lifetime Guarantee. Should a Halfords Advanced hand tool fail while being used for the purpose and in the manner for which it was designed, it will be inspected and replaced. Remember we said that it was the sag, or the angle created due to the sag, to be more specific, which was a key reason behind the torque loss? To further confirm that, a wobble extension was used under the same setting. Even though many people don’t do this and are aware of the science behind it, many don’t. Some people are just comfortable holding a wrench at the very bottom of it, and they do the same for a torque wrench as well.Just a little heads up, make sure you measure the length of the wrench and extension correctly. A couple of centimeters here and there won’t matter much, but don’t miss your mark by inches. The first extension was a 10-inch ½-inch drive impact extension and it averaged out at 33.7 ft-lb, which is a 3.16% torque loss compared to the baseline.

Finally, testing out with an 88-inch extension, the results came out as 9.29% torque loss without the brace and 5.72% loss with the brace. The numbers were not exactly the ones that were expected because the torque loss was rather a little less than the 64-inch extension, but the pattern was somewhat upheld, we could say.It was time for a 38-inch extension and it averaged out at 35.1 ft-lb, which actually is a 0.86% increase in torque from the baseline.

But things got interesting when the wobble came into play. The results were fairly inconsistent when trying out different angles, as summed up below: At this point, no dedicated brace was used even though there was a little sag (spoiler: that’s a key reason behind the torque loss). Now that things were to be stretched further, to minimize the substantial amount of sag, a chair was used as a brace to get as accurate results as possible.

\n\t\t\tHalfords Advanced 1/2\" Drive Impact Extension Bar Set

While doing the same test with a 64-inch extension, the torque loss was 9.77% (without the brace) and 6.23% with the brace. At this point, the sag was so substantial that even after using a brace, a significant torque loss was seen. You just need to know the actual length of the wrench and the extension. That’s it. That’s the apparently obscure part, I suppose.